Friday, May 27, 2022

The Ellensburg, WA sky for the week of May 28, 2022

Saturday: Cygnus the swan flies tonight. Deneb, the brightest star in the constellation, whose name means “tail” in Arabic, is two and a half fists held upright and at arm’s length above due northeast at 10:00 p.m. Cygnus’ wings make a vertical line one half a fist to the right of Deneb. Its head, marked by the star Albireo, is two fists to the right of Deneb. While Deneb is at the tail of Cygnus, it is at the head of the line of bright stars. It is 160,000 times more luminous than the Sun making it one of the brightest stars in the galaxy. It does not dominate our night sky because it is 2,600 light years away, one of the farthest naked eye stars. If Deneb were 25 light years away, it would shine as bright as a crescent moon. Compare that to Vega, its fellow Summer Triangle star. Vega IS 25 light years away and certainly doesn’t rival the light of the crescent Moon. Vega is about two fists to the upper right of Deneb.

Sunday: Stonehenge was created on the island of Great Britain by Neolithic people. “Manhattanhenge” was created on the island of Manhattan by modern day architects and construction workers. Twice a year, the end of May and mid-July, the setting Sun aligns perfectly with the Manhattan grid pattern. That means observers will see the Sun set at the end of the street. The first Manhattanhenge sunset is tonight at 8:13 p.m. Eastern time and then again tomorrow at 8:14 p.m. Eastern time. For more information about Manhattanhenge, go to http://tiny.cc/cd7ytz.

If you can’t visit Manhattan, you can at least get up early and observe Jupiter and Mars very close together in the pre-dawn sky. Mars is about a half a degree below Jupiter. They are both one and a half fists above the east-southeastern horizon.

Monday: Most meteor showers are yearly occurrences that come about due to the Earth annually passing through the orbital path of a comet. The meteors are the tiny bits of the comet left behind, similar to the crumbs left behind by a hiker eating a large cookie. In 1995, Comet 73P/Schwassmann-Wachmann 3 fractured into many pieces, leaving a trail of fragments in its orbit. Some astronomers think this is the year that those particles make their way in front of the Earth, resulting in a large meteor shower tonight. Or maybe not. Since this is the first time the swarm of particles is near the Earth, scientists don’t have enough information to make a universally agreed upon prediction. But why take chances. The peak, if it occurs, will be at about 10:00 p.m. Pacific Time, to the upper right of the bright star Arcturus, about six fists above due south. For more information about the event, go to https://skyandtelescope.org/astronomy-news/update-on-a-possible-outburst-of-meteors/.

Tuesday: The questions who, what, where, and when can only be asked with a “W”. At 9:30 p.m., the W-shaped constellation Cassiopeia is nearly two fists above due north. The middle star in the W was used as a navigation reference point during the early space missions. The American astronaut Gus Grissom nicknamed the star Navi, his middle name Ivan spelled backwards. After he died in the Apollo 1 fire, the star name was kept as a memorial.

Wednesday: Venus is a little more than a half a fist above the eastern horizon at 4:30 a.m.

Thursday: Altair, the lowest star in the Summer Triangle, is one fist above due east at 10:30 p.m.

Friday: As the weather warms up, people start thinking about swimming in a nice cool body of water. A few years ago, astronomers discovered evidence of an ocean about 20 miles beneath the surface of Saturn’s moon Enceladus. NASA’s Cassini probes measured variations in how the moon’s gravity pulled on the orbiting spacecraft. These variations can be explained by a large amount of liquid water under one section of the ice because liquid water is denser than an equal volume of ice. While you need a very large telescope to see Enceladus, you can easily see Saturn less than a half a fist above the southeast horizon at 1:30 a.m. They are both two and a half fists above the southern horizon at 4:30 a.m.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.

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